As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems include enterprise storage systems. To increase rack level drive density for enterprise storage systems, the quantity of hard drives contained within drive enclosures for enterprise storage systems has increased over time. In the past, racked storage enclosure form factors often had a single row of hard drives that were inserted from the front of the system, and storage controllers and power supplies were then inserted from the rear of the system. These existing front load systems hold the single row of drives in a position such that fresh air drawn in from a rear-positioned fan flows from front-to-back across the length of each drive in the single row.
FIG. 1 illustrates a bottom perspective view of a conventional hard drive (3.5 inch HDD) assembly 100 having a cavity 110 that is defined in the bottom surface 102 of the base portion 160 of the casting of the hard drive assembly 100. As shown, drive assembly 100 has a front end 132, a back end 134, and two opposing side walls 136 and 138. Threaded mounting holes 105 are defined in the opposing side walls 136 and 138 of drive assembly 100 to receive complementary threaded fasteners that serve the purpose of securing a drive carrier assembly to the hard drive assembly 100 as further described herein. In FIG. 1, the top portion 150 of the drive assembly 100 is a sealed space that contains the drive media and read/write arm (heads). The base portion 160 of the drive assembly 100 (delineated from top section 150 by dashed lines) generally consists of a drive controller printed circuit board (PCB) assembly 152, a motor housing 153, and has protrusions/ribs 154 for bearings and stiffening features. The base portion 160 is configured to perform multiple roles for the drive assembly 100, including providing shock/rotational vibration (RV)/dynamics dampening, thermal dissipation, front-to-back (longitudinal) air flow, and head/disk interface (HDI) stability.
As shown in FIG. 1, ribs 154 are not sized to be the full height of the drive's casting (i.e., they do not extend to the match the full height of the side walls 136 and 138 of base portion 160). In this regard, the height of ribs 154 is reduced relative to the side walls 136 and 138 to optimize for longitudinal (front-to-back) air flow when drive assembly 100 is deployed in a conventional front load single row drive enclosure system. The side walls 136, 138 of the drive assembly 100 are full height so that the bottom surface of the side walls 136, 138 provides a primary measuring datum for the drive assembly 100. Additionally, many enclosure designers utilize the bottom surface of a drive assembly 100 as a constraint for drive mounting or for drive rails.
FIG. 2 shows the hard drive assembly 100 of FIG. 1 as it may be mechanically coupled to two side components (rails) 202 and 204 of a drive carrier assembly 200 by threaded mounting screws 106 received through mounting holes 107 of drive carrier assembly 200 into threaded mounting holes 105 of drive assembly 100 to form a conventional mountable hard drive system 250. As shown, side mounting rails 202 and 204 of drive carrier assembly 200 are configured to slide along a contiguous rail surface of side walls 138 and 136 of hard drive assembly 100 between the fastener holes 105. As further shown in FIG. 2, drive carrier side components 202 and 204 are configured to support a cross member in the form of a drive handle mechanism 220 there between that allows for insertion and removal of front end 132 of drive assembly 100 from mating relationship with a corresponding mechanism within the drive enclosure that is configured to mount and secure the drive assembly 100 in operable engagement within the drive enclosure. When deployed within a conventional front-loading single row drive enclosure, some cooling airflow advantage is realized due to airflow tunneling from front-to-back through the cavity 110 defined in the bottom surface 102 of the base portion 160 drive assembly 100 as shown by the arrows 290 in FIG. 2.
To gain more drive density, a new class of racked storage dense enclosure has emerged having a form factor that utilizes a drive drawer that is filled with rows of hard drives. FIG. 3 illustrates a cut-away perspective view of one example of drawer and drive components of a conventional drawer-based dense storage drive enclosure 300. As shown enclosure 300 includes a drawer 320 having multiple and parallel rows 310 of closely-spaced hard drive assemblies 100 and their respective corresponding drive carrier assemblies 200 that are oriented side-to-side across the drawer of the enclosure 300, with rear-mounted cooling fans 390 that draw fresh cooling air 350 into the enclosure 300 from the front of the enclosure 300 and expel the warmed cooling air 352 from the back of the enclosure 300. For illustration purposes, chassis enclosure walls that surround drawer 320 and rows 310 of hard drive systems 250 are not shown in FIG. 3. Most of such conventional drawer-based implementations are designed for vertical top loaded insertion of the mountable hard drive systems 250 into the drawer 320, i.e., the hard drive systems 250 are loaded vertically from the top into the drawer 320 of the storage enclosure 300 in a toaster-style fashion with the front 132 of the drive assemblies 100 facing upwards and with one side wall 136 or 138 facing toward the front of the enclosure.
As further shown in FIG. 3, this vertical drive-loading configuration creates airflow and cooling problems for the multiple rows 310a to 310f of hard drive assemblies 100. When a hard drive system 250 is inserted in a vertical fashion in a dense system enclosure, the solid side wall profiles 136 and 138 of the drive assembly 100 and solid side profiles of side components (rails) 202 and 204 of carrier assembly 200 completely block the lateral (side-to-side) flow of cooling air through the drive assemblies as shown by arrows 292 in FIG. 2. The only pathways for air flow through each row of drive assemblies of the dense enclosure drawer is through any provided gaps 398 existing between different adjacent drive assemblies 100 of each row 310 and through any provided gaps 399 present between the enclosure walls and the ends of the rows 310 as shown in FIG. 3.
Due to the multiple side-to-side orientation of the rows of hard drive systems 250, only the front-most row 310a of hard drive assemblies 100 receives fresh cooling air 350 from the front-positioned cooling fans, while each successive row 310b to 310f of drive assemblies 100 toward the rear of the enclosure receives pre-heated air that has already flowed across the previous row/s of hard drive assemblies 100 in the enclosure. At the same time, the close spacing of the hard drive systems 250 within each row acts to restrict the flow of air across the row 310 due to the solid mass of the full-height side walls 136, 138 of the individual drive assemblies 100 that are closely spaced together within each row. This results in an overall reduction in rate of cooling air flow across the drive assemblies 100 of the enclosure. Increasing the gap size between adjacent hard drive systems 250 in the same row 310 more allows for more air flow, but reduces the number of hard drive systems 250 that can be installed in the dense enclosure system. Thus, airflow requirements conflict with drive density desires in conventional dense enclosure systems.